基于Eclipse平台和MySQL数据库超市订货管理系统

/* * This product includes software developed by the * Apache Software Foundation (http://www.apache.org/). */ package ch09.database; import java.sql.Connection; import java.sql.ResultSet; import java.sql.Statement; import java.util.*; import javax.servlet.http.HttpSession; import ch09.*; import ch09.object.unit.*; /** * 针对商品信息的数据处理类 * @author ShenYK * @version 1.0 */ public class DItem extends DCommon { //根据商品ID获取商品对象 public Item getItemById ( String itemId ) throws Exception { //获得数据库连接 Connection conn = this.getDBConnection(); if ( conn == null ) { throw new Exception("数据库连接获得失败！"); } Statement stmt = null; ResultSet rs = null; try { //从数据库中抽取数据 stmt = conn.createStatement(); //执行SQL语句 String sQuery = "select * from item where item_id='" + itemId + "' "; rs = stmt.executeQuery( sQuery ); if ( rs.next() ) { Item oItem = new Item(rs); return oItem; } else { return null; } } catch(Exception e) { e.printStackTrace(); throw e; } finally { try { rs.close(); stmt.close(); conn.close(); }catch(Exception ex) { } } } //根据商品分类ID获取商品分类对象 public Category getCategoryById ( String categoryId ) throws Exception { //获得数据库连接 Connection conn = this.getDBConnection(); if ( conn == null ) { throw new Exception("数据库连接获得失败！"); } Statement stmt = null; ResultSet rs = null; try { //从数据库中抽取数据 stmt = conn.createStatement(); //执行SQL语句 String sQuery = "select * from category where category_id='" + categoryId + "' "; rs = stmt.executeQuery( sQuery ); if ( rs.next() ) { Category oCategory = new Category(rs); return oCategory; } else { return null; } } catch(Exception e) { e.printStackTrace(); throw e; } finally { try { rs.close(); stmt.close(); conn.close(); }catch(Exception ex) { } } } //登录新商品 public String registerNewItem ( Item oItem ) throws Exception { //获得数据库连接 Connection conn = this.getDBConnection(); if ( conn == null ) { throw new Exception("数据库连接获得失败！"); } Statement stmt = null; ResultSet rs = null; try { //从数据库中抽取数据 stmt = conn.createStatement(); //执行SQL语句生成最大的itemId String sItemId = ""; String sQuery = "select max(item_id) from item"; rs = stmt.executeQuery( sQuery ); rs.next(); String sCurrentMaxId = rs.getString(1); //当前是第一次登录 if ( sCurrentMaxId == null ) { sItemId = "000001"; } else { int iMaxCd = Integer.parseInt(sCurrentMaxId); sItemId = String.valueOf(iMaxCd+1); int iLength = sItemId.length(); for(int i=6; i>iLength; i--) { sItemId = "0" + sItemId; } } //执行SQL语句，添加商品信息 String sInsertQuery = "insert into item set " + "item_id = '" + sItemId + "', " + "item_name = '" + oItem.getItemName() + "', " + "short_name = '" + oItem.getShortName() + "', " + "category = '" + oItem.getCategory() + "', " + "standard = '" + oItem.getStandard() + "', " + "place = '" + oItem.getPlace() + "', " + "unit = '" + oItem.getUnit() + "', " + "product_id = '" + oItem.getProductId() + "'"; stmt.executeUpdate( sInsertQuery ); return sItemId; } catch(Exception e) { e.printStackTrace(); throw e; } finally { try { rs.close(); stmt.close(); conn.close(); }catch(Exception ex) { } } } //修改商品 public void modifyItem ( Item oItem ) throws Exception { //获得数据库连接 Connection conn = this.getDBConnection(); if ( conn == null ) { throw new Exception("数据库连接获得失败！"); } Statement stmt = null; ResultSet rs = null; try { //从数据库中抽取数据 stmt = conn.createStatement(); //执行SQL语句，添加商品信息 String sUdpateQuery = "update item set " + "item_name = '" + oItem.getItemName() + "', " + "short_name = '" + oItem.getShortName() + "', " + "category = '" + oItem.getCategory() + "', " + "standard = '" + oItem.getStandard() + "', " + "place = '" + oItem.getPlace() + "', " + "unit = '" + oItem.getUnit() + "', " + "product_id = '" + oItem.getProductId() + "' " + "where item_id = '" + oItem.getItemId() + "'"; stmt.executeUpdate( sUdpateQuery ); } catch(Exception e) { e.printStackTrace(); throw e; } finally { try { rs.close(); stmt.close(); conn.close(); }catch(Exception ex) { } } } //删除商品 public void deleteItem ( String sItemId ) throws Exception { //获得数据库连接 Connection conn = this.getDBConnection(); if ( conn == null ) { throw new Exception("数据库连接获得失败！"); } Statement stmt = null; ResultSet rs = null; try { //从数据库中抽取数据 stmt = conn.createStatement(); //执行SQL语句，删除商品信息 String sUdpateQuery = "delete from item where item_id = '" + sItemId + "'"; stmt.executeUpdate( sUdpateQuery ); } catch(Exception e) { e.printStackTrace(); throw e; } finally { try { rs.close(); stmt.close(); conn.close(); }catch(Exception ex) { } } } //登录新商品分类 public String registerNewCategory ( C